Field of Invention
The present invention relates to measurement instruments in the field of shoe-making industry, and specifically to a last that can measure magnitudes and distribution of forces from various parts of a shoe upper surface in a shoe-making process.
Description of Related Arts
In a shoe-making process, the last plays a very important role. The shape of the last represents the shape of a human foot, and determines the shoe style and model. In a shoe design and sample-making process, a model designer designs contours of shoes, and the shape and size of each splice material; and uses the last to make a prototype, adjust the prototype, and carry out a trial-production. During the trial-production, due to the material, model and the like, the shoe does not fit with the last, and forces in various parts of the upper are not uniform; consequently, the upper surface is folded and twisted, and two ends of the shoe are upturned after the shoe is shaped and removed from the last. In this case, the model designer needs to re-adjust the model of the upper; however, because no specific data is available to locate problems and explain causes of the problems, the model designer can only rely on personal experience, judgment and continuous trial-productions to adjust and improve the model. The subjectivity of judgment and differences in personal experience make standardized operations impossible. Continuous trial-productions not only waste a lot of materials but also result in a waste of trial-production working hours and research and development time.
Currently, during manufacturing of shoes, there are no instruments capable of measuring three-dimensional forces applied to an internal last by a shoe upper surface after lasting of a shoe, and determining whether a problem exists in the material or model of the shoe by obtaining distribution of the three-dimensional forces on the internal last of the shoes so as to help the model designer modify the model and adjust the material more quickly and accurately.
In view of the foregoing existing problems, an objective of the present invention is to provide a digital mechanical measurement last which is capable of measuring three-dimensional forces applied to an internal last by a shoe upper surface after lasting of a shoe to analyze problems existing in the model and material of the shoe upper surface and locate the problems, so as to help a model designer to modify a paper pattern and adjust the material more quickly and accurately.